fbset vs modelines help

[Oliver George <o_george@postoffice.utas.edu.au>]

Hi Guys,

I'm really struggling with fbset, any help would be greatly appreciated.

I have a happy little debian notebook which runs XFree86 fine, what I'm attempting to do is get a 800x600 console happening (native LCD resolution).  The thing which seems to be stumping me is getting a sensible fbset configuration, all the predefined modes (including the 800x600-60 which should work) fail, the console shows slowly streaking lines (and in other cases crazy coloured lines!).

This is what the XFree86 config tells me...

...
(--) ATI(0): 800x600 panel (ID 1) detected.
(--) ATI(0): Panel model Hitachi TX31D35VC1CAA.
(--) ATI(0): Panel clock is 39.871 MHz.
(II) ATI(0): Using digital flat panel interface.
...
(II) ATI(0): Not using built-in mode "Native panel mode" (hsync out of range)
(--) ATI(0): Virtual size is 800x600 (pitch 800)
(**) ATI(0): Default mode "800x600": 39.9 MHz, 38.9 kHz, 62.9 Hz
(II) ATI(0): Modeline "800x600"   39.87  800 824 896 1024  600 600 603 619 +hsync +vsync
...

I'm sure this should translate into something i can tell fbset but I need help making it work.  This is what i concluded from the Frame Buffer FAQ...

=========================================================
#!/usr/bin/env python

DCF=39.87;HR=800;SH1=824;SH2=896;HFL=1024;VR=600;SV1=600;SV2=603;VFL=619

left= HFL - SH2
right= SH1 - HR
hslen = SH2 - SH1
upper= VFL - SV2
lower= SV1 - VR
vslen = SV2 - SV1

pixclock = 1000000/DCF

print "fbset -g", pixclock, left, right, upper, lower, hslen, vslen
========================================================

and based on this i run...
  modprobe atyfb
  fbset -t 25081 128 24 10 0 72 3 -g 800 600 800 600 4

notably the streaks are very slow (not just flicker) so perhaps i'm close... can anyone please offer some guidance.

thanks heaps, Oliver.